Method of making chains.



. F. CRAVEN.

' 0F MAKING CH S.

A |o N FILED uLYl 5.

1,242,325, Patented Oct. 9,1917.

Www.

JAMES F. CBAVEN, 0F PITTSBURGH, PENNSYLVANIA.

METHOD or MAKING .cHAINs specification of Letters raient.

. Patented ect. a, 1era Application led July 14, 1916. Serial N o.109,264.

This invention relates to a method of making weldless or solid linkchains, by forging the same directly from a bar, thereby dispensing withwelding operations.

The object of the invention is to provide a method of making chains ofthe charac-y ter described whereby the metal rod or bar is formed into achain of weldless links without waste of metal, and whereby all of theoperations can be effected by means of strong, simple and durable toolsacting transversely to the axis of the bar and simultaneously fromopposite sides thereof. A further object of the invention is to providea method for making chains of thefkind described in which the tools foreffecting the successive operations upon the bar to convert it into afinished chain act simultaneously upon successive links, thereby greatlyexpediting the transformation of the bar into the chain.

The invention comprises the several method steps hereinafter describedand claimed.

In the accompanying drawings, Figure 1 j is a diagrammatic viewillustrating theman-l lner .of transforming the bar into a cham andshowing suitable dies for effecting the several operations; Fig. 2 is aplan view of the bar and chain links shown 4in Fig. 1; Fig.

.3 is a transverse section on the line 3 3, Fig. 1; Fig. fl is a similarsection on the line 1 -4, 1; and Fig. 5 is a plan viewv of one of thesecond set of dies.

In the drawings, 1 represents a suitable bar from which the chain isformed, said bar preferably beingof cruciform cross section, as shown in4 pairs of oppositely disposed webs :2, 2 and 3, 3. In transforming thisbar into a chain of weldless links,vit is subjected t0 the action ofsets of oppositely disposed dies or tools acting simultaneously onopposite faces of said bar, and between successive strokes of said diesor tools the bar is rotated on its axis through an angle of 90, wherebythe dies act on the bar successively in directions at right angles toeach other.

The first set of dies 4 act by pressure ig. 3, having the twov 'againstthe edges of, oppositely disposed webs of the bar and are so formedas toiny dent said webs and entirely separate the same without removin any ofthe metal and also to press indentatlons into the core of y the bar, andas shown have the central projecting portions 5 whichengagethe edges ofoppositely disposed webs and indent the same, and with curved cavities 6forwardly and backwardly of the projections 5 and bounded by cheekportions 7 which prevent the metal displaced by the projection 5 fromfiowing sidewise. Thecavities 6 are of substantiallythe contour of theend portions 8 .of adjacent'links, so that the action of these dies isto entirely separate thetop and bottom webs of the bar and also to pressindentations 9 into the core of the bar, which indentations almost, butnot completely,',punc ture the same, leaving only thin web portions 10.The extreme ends of .the projections 5 are preferably slightly wedgeshape, as vshown at 11, so as to score the webs 10 at their .centrallongitudinal lines for guiding the next succeeding set of dies. Theeffect of the dies 4 is to form the bar into successive portions ofapproximately the shape of crude links, lwith the metal inclosed by eachlink quite' thin.

The next set of dies 12 are of substantially the shape shown in Figs.1,4 and 5, the same having projecting portions 13, that of the 'top dielying 'on one side of the longitudinal line of the bar being formed, andthat of the'bottom die lying on the opposite side of said longitudinalline, so thatA said projecting portions will pass each otheras the diescome together, and which projecting portions are pointed .so as touncture the thin webs 10 inclosed by the link, but without removing anyof the metal,'-'said projecting.

portions toward their bases being widened `approximately the form of vachain having.

circular links, but in which said links are still integrally connectedby the iin portions 16.

The lin portions 16 are confined or inclosed by the links so that the`are not Wholly exposed, and ILOxmally can e reached opposite sidesthereof.

only by tools a plied at an angleof 45 to thel plane of t e connectedlinks. 'llools adapted to act on this connecting iin to sever the samewhenthe links are-in normal position are `required to be ofsmall sizeand therefore are neither strong nor durable. In carryin out my method,after the links are forme by the first two sets of dies t and 12, one ofthe links 'of the connected series, such as the link 17, is shiftedrelatively to the link 18, to which it `is connected, in order to exposethe fm 16 to the direct action of a large, simple and strong tool. Thisshifting is accomplished by moving the exposed'linkl? while the reminderof the partially formed links are rmly held in clamps or dies, in amanner to bend or rotate the link 17 around an axis perpendicular to theplane of the link 18, or in other words, twisting the link around itsportion 19 which is still integrally attached to the link 18. ITheextent of this rotation maybe varied, but should be not less than 90,and is shown as rotated through considerably more than 90, from thedotted line position to the full line position shown in Fig. 2. In thisposition the tin .16 connecting` the two links is exposed from above andbelow,

so that it can be reached by the direct action of a tool working normalto the plane of the bar or chain being formed. This severing tool isshown in the form of a pair of oppositely disposed dies20, which areprovided with sharp projecting edges 21, which pinch through said 1infrom o posite sides and thus sever the same, the ack of'said projectionsbeing slightly concave so as to round the end portion ofthe link 18, andthe dies at their forward portions being provided with the grooves 23which forge the severed fin into the end portion of thev link 18.

As standard chain links are of oblong form and the links have beenopened out to substantially circular form by the dies 12, it isdesirable to afterward flatten the links. rlhis can be accomplished byproviding the dies 20 with grooves 24 which exert pressure upon the link17 from above and below, and press the same into oblong form.

rllhe dies 4f, 12 and 2O act successively upon di'erent link portions ofthe partially formed chain, and by direct pressure on .Between each ofthese operations the bar is rotated on its axis through 90, so that saiddies act succes-` sively upon portions of the barat right angles to eachother. Since all of these operations are upon successive link portionsof the bar and are purely pressing or forging operations upon twoopposite sides ofthe bar, it is possible to mount these three sets ofdies upon a single die block or head, and in actual practice all of saiddies are actuated by a common pressing head and act naeaaassimultaneously upon successive portions of the partially formed bar. Byperforming -these successive steps simultaneously upon rlhe process isentirely a erging or pressure e operation, and is effected,v as will beobserved, wlthout removing or wasting any of y the metal, so that thefinal `nished chain will be substantially' the same weight asthe barfrom which kit is formed.

When the links are twisted or rotated as above described, in order toexpose the connecting lin, that portion of the link which is beingturned to one side, which threads down through the link to which it isstill connected, can, of course, not rotate `and therefore this portionof the link is subjected to twisting or torsional action, which not onlya'ects that portion which threads down through the link to which it isstill connected, but also extends somewhat around into V4the upper andlower portions of the link.. rl`he subjection of this'portion of themetal to the torsional action increases the tensile strength of themetal, and increases this to the greatest extent at thepoint where thetwo links connect to each other, that is, the vend portions of thelinks, and where such links are subjected to the greatest wear andstress and where failure usually occurs. The severing of the connectingfin in the manner described without removing any of the metal alsoreinforces the'end portions of the links by the fact that the metal ofthe connecting fin is worked into the end portions of the links.

ln commercially carryin out the method, it will be performed pre erablyby automatic machinery in which the bar will be' vfed forward step bystep between the successive strokes of the dies, and also rotated to 90between successive strokes of the dies. The machine will be soconstructed that th' unformed bar and partly formed links wil be tightlyclamped and rigidly held, so that the metal which is displaced by thepressure of the dies, will be caused to How largely toward the free end,that is, toward the unforrned portion of the bar.

lf necessary the links after being completely severed can be subjectedto further die action in order to smooth them up and reduce anyirregularities and tins which may remain, but ordinarily this will notbe neceslid'hat li claim is 1. The method of making solid or weldlesschain, which consists in taking a suitable bar, indenting the sanne onopposite sides by pressure without removing any of the metal to formportions of approximately the shape of chain links, and then puncturingthe metal inclosed by the links and opening the same out by pressing themetal sidewise, said indenting and puncturing being effected by lateralpressure in the saine plane.

2. The method of making solid ,or Weldless cha-in, which consists intaking a bar cruciform in cross section, indenting opposite webs byedgewise pressure without removing any of the metal to form portions ofapproximately the shape of chain links, and then puncturing the metalinclosed by the links and opening the same out by pressing the metalsidewise, said indenting and puncturing being effected by lateralpressure in the same plane.

3. The method of making solid or weldless chain, which consists intaking a suitable bar, indenting the' same on opposite sides by pressurewithout removing any of the metal to form portions of approximately .theshape of chain links, then puncturing the metal inclosed by the linksand opening the same out by pressing the metal si-dewise, then shiftingtwo successive links relative to each other around an axis transverse tothe bar to expose the connecting fin. and finally severing said fin toseparate said links.

4. The method of making solid or weldless chain, which consists intaking a suitable bar and indenting the same from opposite sides bypressure without removing any of the metal to form portions ofapproximatelythe shape of chain links. then punc-v turing by pressingaside the metal inclosed by said links and opening the links out intocircular form, then shifting two successive links relative to each otheraround an axis transverse to the bar to expose the connecting fin, andfinally severing sid fin to separate said links and simultaneouslyflatten said circular link to oblong form. l

5. The method of making solid or weldless chain, which consists intaking a suitable bar, indenting the same on opposite sides by pressurewithout removing any of the metal to form portions of approximately theshape of chain links. then puncturing the metal inclosed by the linksand' opening the same out by pressing the metal sidewise, and finallyseparating adjacent links. said indenting, puncturing and separatingoperations being effected by lateral pressure in the same plane.

6. The method of making solid or weldless chain. which consists intaking a suitable bar, indenting the same from opposite sides bypressure without removing'the metal to form portions of approximatelythe shape of chain links, then puncturing and opening out the vlinks bypressing aside the metal inclosed thereby, then shifting two successivelinks'relative to each other around an axis transverse to the bar toexpose the connecty ing fin, and finally severing said fin to separatesaid links` said indenting, said puncturing and opening out and saidsevering of the fin being performed simultaneously upon successive' linkportions by pressure in the same plane.

7. The method of making solid or Weldless chain, which consists intaking a bar cruciform in cross section, indenting opposite'webs byedgewise pressure without removing any of the metal to form portions ofapproximately the shape of chain links, then puncturing the metalinclosed by the links and opening the same out by pressing the metalsidei'vise, then shifting two successive links relative to each otheraround an axis transverse to the bar to expose the connecting fin, andfinally severingsaid fin to separate said links.

S. The. method of making solid or weldless chain. which consists intaking a bar cruciform in cross section and indenting opposite webs byedgewise pressure without removing any of the metal to form portions ofapproximately the shape of chain links, then puncturing by pressingaside the metal inclosed by said links and opening the links out intocircular form. then shifting two successive links relative to each otheraround an axis .transverse to the bar lto expose the connecting fin. andfinally severing said fin to separate said links and simultaneouslyHatten said circular link to oblong form.

9. The method of making solid or weldless chain, which consists intaking a bar eruciform in cross section, indenting opposite webs byedgewise pressure without removing the metal to form portions ofapproximately the shape of chain links, then puncturing and-opening outthe links by pressing aside the metal inclosed thereby, then shiftingtwo successive links relative to each other around an axis transverse tothe bar to expose the connecting fin, and

finally severing said fin to separate said

